instinct

Meaning: In the instinct theory of motivation, organisms are born with biologically programmed behaviors that promote survival and reproduction. These behaviors appear without learning, are set off by a specific stimulus, and look much alike across a species. Examples are rooting and sucking in newborns and nest building in birds. In animal behavior (biology), the related idea is the fixed action pattern, a stereotyped sequence that usually runs to completion once triggered.

On the MCAT: Passages set instinct theory beside other motivation theories. Drive-reduction theory says a physiological need creates a drive, such as hunger, and behavior reduces it to restore homeostasis. Arousal theory says people seek an optimal level of arousal. Incentive theory says external rewards pull behavior. You may be given a behavior and asked which theory fits. Unlearned, universal, stimulus-triggered behavior points to instinct.

Common confusion: An instinct is not a drive. A drive is the internal tension from an unmet need, while an instinct is an inherited behavior pattern. An instinct is also not a reflex, which is a simpler, automatic response. Instinct theory is criticized as circular, because naming a behavior an instinct does not explain it. It also underweights learning and cultural variation.